Toni Reichelt A Model Driven Approach for Service Based System Design Using Interaction Templates Wissenschaftliche Schriftenreihe EINGEBETTETE, SELBSTORGANISIERENDE SYSTEME Band 10 Prof. Dr. Wolfram Hardt (Hrsg.) Toni Reichelt A Model Driven Approach for Service Based System Design Using Interaction Templates Chemnitz University Press 2012 Impressum Bibliografische Information der Deutschen Nationalbibliothek Die Deutsche Nationalbibliothek verzeichnet diese Publikation in der Deutschen Nationalbibliografie; detaillierte bibliografische Angaben sind im Internet über http://dnb.d-nb.de abrufbar. Zugl.: Chemnitz, Techn. Univ., Diss., 2012 Technische Universität Chemnitz/Universitätsbibliothek Universitätsverlag Chemnitz 09107 Chemnitz http://www.bibliothek.tu-chemnitz.de/UniVerlag/ Herstellung und Auslieferung Verlagshaus Monsenstein und Vannerdat OHG Am Hawerkamp 31 48155 Münster http://www.mv-verlag.de ISBN 978-3-941003-60-6 URL: http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-85986 Preface to the scientific series “Eingebettete, selbstorganisierende Systeme” The tenth volume of the scientific series Eingebettete, selbstorganisierende Systeme (Em- bedded, self-organised systems) devotes itself to the model driven design of service-oriented systems. Fields of application for such systems, amongst others, range from large scale, distributed enterprise solutions down to modularised embedded systems. The presented work was moti- vated by the complex design process of avionics for unmanned systems, where the increased demand for enhanced system autonomy implies high levels of system collaboration and infor- mation exchange. For such system designs a clear separation between the application logic implemented by system components, the means of interaction between them and finally the realisation of such communication on target platforms is essential. In particular, this sep- aration leads to simplification of the complex design processes and increases the individual components’ re-use potential. With the presented work, Dr. Reichelt provides a holistic model driven design process for such systems. The design of service oriented systems and their target platform independent modelling with respect to component interaction stay in the focus of his work. The concrete semantics of individual interactions are condensed into interaction templates collected in an extensible model library. In turn, this library then provides the building blocks for service and system modelling by means of template instantiation. Dr. Reichelt reflects his formal concepts in a comprehensive UML profile and presents an encapsulating design process. This new design process is validated with a representative case study based on a prototyped tooling environment comprising model transformation and code generation techniques. I am glad that Dr. Reichelt publishes his research in this scientific series and wish you an interesting insight to the field of model driven design of service-oriented systems. Prof. Dr. Wolfram Hardt Chair of Computer Engineering Dean of the Faculty of Computer Science Scientific Director of Computing Center Chemnitz University of Technology, Germany April 2012 A Model Driven Approach for Service Based System Design Using Interaction Templates Dissertation Submitted in partial fulfilment of the requirements for the degree of Doktoringenieur (Dr.-Ing.) presented to the Faculty of Computer Science Chemnitz University of Technology Submitted by Toni Reichelt Assessor: Prof. Dr. Wolfram Hardt Prof. Dr.-Ing. Martin Gaedke Acknowledgements This thesis would not exist without the extensive support and encouragement by many people. First of all I am grateful to my mentor Prof. Dr. Wolfram Hardt who supported me in pursuing a PhD degree. Within fruitful discussions he helped shaping and organising many of the ideas of this thesis. And as this thesis was prepared in an industrial environment I am especially thankful because he always welcomed me in academia and allowed me to stay in touch with the scientific world. I would also like to thank Prof. Dr.-Ing. Martin Gaedke for his interest in this thesis and very constructive feedback in structuring and improving the presented work. It is an honour for me to thank some personal friends with whom I had the pleasure to work with at Cassidian. In particular I am indebted to Dr. André Windisch and Dr. Norbert Oswald. André, thank you for introducing me to Cassidian and the world of avionics. Norbert, I am thankful for given me the opportunity to join the EPAS (Engineering Platform for Autonomous Systems) team which provided an ideal framework for developing my ideas and test driving solution concepts. Also, I thank my friends Dr.-Ing. Stefan Förster and Herwig Moser for their almost end- less willingness to discuss many ideas compiled into this work as well as proof-reading and commenting on its final version. Finally, I would also like to thank my family, especially my wife Conny. Without their continous support this work would not have been possible. Thank you. Toni Reichelt Munich, August, 2011 i ii Abstract Based on the increasing complexity of modern avionics, the associated system design pro- cesses moved towards Model Driven Architecture (MDA) based processes. Additionally, the demand for higher system autonomy features requires means to further modularise mission systems and to define and establish interactions among the systems’ individual components. Therefore, the ideas of service-oriented computing are currently adapted to established, model driven design processes. With respect to modelling interactions for service com- ponents, current approaches are limited to only a fixed set of communication primitives, restricting a service designer’s expressiveness to specify service interaction. In consequence, interaction patterns not included in this basic set have to be reflected in application code, mangling application and communication logic. Furthermore, when service functionality relies on communication semantics which are not provided by the underlying set of prim- itives, additional emulation behaviour has to be added to the service which makes this mangling even worse. Platform independence is reduced as services can not easily be ported to platforms not natively supporting the selected primitives which contradicts the ideas of model-driven development. Addressing these limitations, this thesis proposes a new model-driven service development process based on Interaction Templates (ITs), promoting interactions among service partic- ipants to first class modelling entities. The process focuses on modelling the interactions among service participants. Interaction semantics are explicitly specified in models, be- yond pure stereotyping, and gain increased platform independence for services with respect to communication. The process exploits automated Model-to-Model (M2M ) and Model-to- Text (M2T) transformations to assist service implementation and to automatically derive interaction realisations on concrete target platforms. This allows for easy replacement and inter-mixing of communication middleware to realise a service’s interactions. This way, ser- vices become independent of the underlying communication primitives by only relying on ITs and not platform primitives which are hidden behind ITs. In turn, realising ITs on concrete platforms is not affected by their utilisation for service interaction. Beside the novel modelling process itself, the presented work defines a Unified Modeling Language (UML) profile, referred to as UML Profile for Interaction-centric Services (UP4IS), which directly supports the adaptation of standard UML language constructs and tools for the proposed modelling approach. The whole development process is demonstrated via the iii specification of a simple video recording systems consisting of two services. The services themselves are based on a representative IT library which forms an essential part of the presented case study. Using these service and IT models, the thesis emphasises the necessary model transformation and code generation steps to derive service implementations based on the abstract models. iv Contents Abstract iii Contents v List of Tables xi List of Figures xiii List of Listings xvii List of Acronyms xix 1 Introduction 1 1.1 Motivation and Application Context . .1 1.2 Problem Description . .2 1.3 Solution Requirements and Contributions . .4 1.4 Outline . .5 I Foundations 7 2 Related Work 9 2.1 Modelling Service Oriented Systems . .9 2.1.1 Formal Frameworks . .9 2.1.2 Architectural Frameworks . 12 2.1.3 Modelling Services with UML . 13 2.1.4 Discussion . 15 2.2 Service Interactions . 15 2.2.1 Interaction Patterns . 15 2.2.2 Catalogues for Service Interaction . 17 2.2.3 Modelling Service Interactions . 17 2.2.4 Service Adaptors . 19 v Contents 2.2.5 Discussion . 21 2.3 Discussion . 21 3 Model Driven Architecture 23 3.1 Methodology . 23 3.2 The Model in the Model Driven Architecture . 24 3.2.1 The Modelling Hierarchy . 24 3.2.2 Platform Independence of Models . 25 3.3 Model Transformations . 26 3.3.1 Source and Target Models . 27 3.3.2 Transformation Strategies . 28 3.3.3 Transformation Languages . 29 4 The Unified Modeling Language 33 4.1 Component Diagram . 33 4.1.1 Description . 33 4.1.2 Visualisation . 33 4.2 Composite Structure Diagram . 35 4.2.1 Description . 35 4.2.2 Visualisation . 36 4.3 Collaboration Diagram . 36 4.3.1 Description . 36 4.3.2 Visualisation . 38 4.4 Sequence Diagrams . 38 4.4.1 Description . 38 4.4.2 Visualisation . 41 4.4.3 Relation to Message